| 摘要 |
An optical pickup and a disc drive apparatus are provided with a plurality of light emitting elements (9a, 9b, 10a) for projecting laser beams having wavelengths of approximately 405nm, 660nm and 780nm respectively, corresponding to a plurality of types of disc-shaped recording media (100), and an objective lens (18) for collecting the laser beams projected from a plurality of the light emitting elements so as to form an elliptical beam spot on a recording plane of the disc-shaped recording media. A long axis of the beam spot of the laser beam having a wavelength of approximately 660nm is directed in a direction at 45° to 65° to a tangential direction of the disc-shaped recording media, and a long axis of the beam spot of the laser beam having a wavelength of approximately 405nm is directed in a direction at 25° to 45° to the tangential direction. Thus, information signal reading performance to the different types of disc-shaped recording media can be improved without increasing the cost.
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